This Knowledge Base article explains how to manage the password for your OpenPGP key.
There are options to store or cache your password. Open macOS System Preferences > GPG Suite, this may still be using the old name with your installation 'GPGPreferences'.
When you store a password in macOS keychain, pinentry, the program used to ask for your password, will never again ask for that password. macOS will remember this password and automatically use it when needed. That means you will no longer see the pinentry dialog querying for your password. The password is protected with your macOS user password. To see stored OpenPGP passwords in macOS Keychain Access:
- open macOS Keychain Access (not GPG Keychain)
- enter 'gnupg' in the search field
- double click any search result and then tick the 'Show password' checkbox
To enable this option, navigate to System Preferences > GPG Suite (old name: GPGPreferences). In the password section tick the 'Store in OS X Keychain' option. The pinentry dialog asking for your password also has that checkbox.
GPG Suite preferences pane (old name: GPGPreferences) password section also has the option to set a certain time your password can be cached. Enter any amount of seconds for which you want your password to be remembered. Password queries after that time period will again show pinentry asking for your password.
The 'Clear' button allows to clear the cache and delete all OpenPGP passwords stored in the macOS keychain access.